My wife thinks the Parkzone Vapor is too fast in the apartment and she wants me to build something slower for indoor flight.
Here are the parts I'm working with
Vapor gearbox and motor
Vapor battery and the batt cable to connect
Vapor prop or a CF one I have laying around
AR6300 RX nanolite 2G
Blue Arrow 3.6 g servos (3)
T-Bird 6A nanolite 4 g

I'm hoping the RX likes 3.7 v as well as the ESC. These are questionable.

Also I want to build it out of 3mil Depron and I have plenty of that super small CF laying around in tubes, square tubes, flats and solid round.

Sorry to break this to you, but to slow down more than the vapor, you will need lighter wing loading. To do that with the equipment you mention might happen with a 2 meter wingspan, or it might not at all depending on the weight of your depron. A plane of this size wouldn't be the best for most apartments or living rooms I have seen.
You could build a nice 3D plane with the items you mentioned (of course the vapor motor and gearbox would not be an option) and have it fly very slowly with a high attitude. Although I wouldn't fly one in my house, others do.

My wife thinks the Parkzone Vapor is too fast in the apartment and she wants me to build something slower for indoor flight.
Here are the parts I'm working with
Vapor gearbox and motor
Vapor battery and the batt cable to connect
Vapor prop or a CF one I have laying around
AR6300 RX nanolite 2G
Blue Arrow 3.6 g servos (3)
T-Bird 6A nanolite 4 g

I'm hoping the RX likes 3.7 v as well as the ESC. These are questionable.

Also I want to build it out of 3mil Depron and I have plenty of that super small CF laying around in tubes, square tubes, flats and solid round.

Maybe a bipe?

Yikes! The total weight of your electronics is going to end up being the same as the Vapor's AUW.

If you're determined to kitbash together an ultra-slow indoor flyer, then buy a Vapor RX board and base your build around that.

I think you are right.....
OK..I'll add another wing to my Vapor and build a light 3d bipe.
Wing is ordered but now I need to figure out how high to mount it to maximize effeciency and slow flight.

Now...which light 3D bipe should I build. I have several 1300 and 1500 Blue Wonder motors and a 9g 12A ESC laying around. I have 3 and 6 and 9mil EPP and Depron and lots of CF for support/bracing/whatever...

I received the AR6300 today and my GOD...2G of coolness.
Of course that Vapor brick is nice but only 3 channels.